cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A050239 Consecutive square palindromic primes; palindromic primes of the form x^2 + (x+1)^2, where x values are given by A050236.

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%I A050239 #26 Aug 03 2025 03:48:06
%S A050239 5,181,313,3187813
%N A050239 Consecutive square palindromic primes; palindromic primes of the form x^2 + (x+1)^2, where x values are given by A050236.
%C A050239 No other terms < 10^20. - _Patrick De Geest_, Aug 15 1999
%H A050239 Patrick De Geest, <a href="http://www.worldofnumbers.com/sumsquare.htm">Palindromic Sums of Squares of Consecutive Integers</a>
%H A050239 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_014.htm">Puzzle 14. Pal-Primes and sum of powers</a>, The Prime Puzzles & Problems Connection.
%H A050239 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PalindromicPrime.html">Palindromic Prime</a>
%t A050239 Select[Total/@Partition[Range[1300]^2,2,1],PalindromeQ[#]&&PrimeQ[#]&] (* _Harvey P. Dale_, Aug 19 2022 *)
%Y A050239 Cf. A050236.
%Y A050239 Subsequence of A002385.
%K A050239 nonn,nice,hard,base,more
%O A050239 1,1
%A A050239 _Eric W. Weisstein_